Catheters are universally used to administer fluid, medicine or parenteral nutrients, withdraw blood, aspirate an embolism, or monitor a patient in need of medical attention. An over-the-needle catheter is used to access a blood vessel, the needle is withdrawn and IV tubing is coupled to the proximal end catheter hub via a luer-lock connector. As the needle is removed from the catheter, the clinician simultaneously places a digital pressure on the catheter tube in the vessel to constrict the fluid path to stop blood leaking from the catheter hub into the workplace, and in doing so, reduces the probability of a blood exposure to the clinician. If the clinician fails to constrict the fluid path, blood is free to flow from the patient and out of the sheath, creating a potential blood exposure for the clinician.
Introducer sheaths and tear-away sheaths are widely used to facilitate vascular or bodily access into a patient. The core or obturator of the introducer sheath or tear-away sheath is withdrawn leaving the distal portion of the sheath positioned in the patient and the proximal end of the sheath outside the patient. Some tear-away sheaths include duck-bill valves in an attempt to limit blood loss. However, blood typically leaks through the sheath.
Fluids administered to a patient through an IV catheter are delivered through a series of tubes, connectors and valves. In-line infusion, or needleless valves and connectors are classified in use as: split septum (creates negative displacement); capped luer (creates negative displacement); mechanical valve (creates negative displacement); and surface septum (creates positive displacement). Negative or positive endolumenal displacement in the fluid path is well known in the medical literature to cause catheter occlusion via blood reflux.
A number of safety IV catheters now include a luer-activated valve comprising a longitudinally movable piston, co-operable resilient duck-bill or split septum membrane positioned orthogonally to the piston axis, requiring these split septum flaps to be stored in a stressed or deformed state the entire time the needle resides in the catheter hub. This means the flaps are deformed from the time components are assembled until the device is used. Resilient material takes a “set” when it is positioned in a configuration that differs from its original formed configuration. With an extended shelf life of up to 5 years, the material integrity of the split septum flaps degrades and fatigues significantly, and performs poorly and leaks when the needle is finally removed after the IV catheter is advanced into the patient. The movement of the piston also displaces fluid in the fluid path, creating positive endolumenal pressure when the piston moves distally, and creating a negative endolumenal pressure when the piston moves proximally, increasing the probability of catheter occlusion. These split septum/piston valves also require the catheter hub dimensions to be increased, both outside diameter and length, adding mass to the device, adding bulk to the packaging and medical waste stream, and altering the clinician's proprioception associated with IV catheter placement.